Improvement in steam engines



H O. LOTHROP.

STEAM ENGINE. 6

Patented July 16, 1867.

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IMPROVEMENT IN STEAM ENGINES.

ttecigrhiile nimm .it in ttfsriitersmeut mit making anni its sans TO ALL PERSONSTO WHOM THESE PRESENTS SHALL ,COMEz Be it known ,that I, HENRY O.' LoTrxnoP, et'- Milford,.n the county of Worcester, end Stute of Massachu. s etts` have invented a new and useful Steam Engine; vund do herebydeclare the sume to be lul'l'y descifibedin the follov'ving specification, and represented inthe accompanyingdrawings, of which- Figure 1 is u. top view, and

Figure 2 n longitudinal section `of' it.

FigureB is a. transverse section, taken through the middle of the cylinder, and its steam-receiving and exhaust-chambers. 7 u 'i Figure 4 is s. longitudinal section of one o f thevalvc cases or 'chambers snd'its cylindrical valve.

Figure 5 is a horizontal section of the two vulves'and their chouchou.-

Figure 6 is n vertical section of the sliding-'crank and its'cnm, applied to the innerend of the driving-shaft of theengine. l v

A peculisrity of this engine, wherein it differs from many others, consistsiu its having three pistons arranged within und to operate with one-cylinder, the seid cylinder heingopenat each end, the object of the whole-being to cause stenin on und sfterfentering the cylinder Ito move one of the said pistons in one Ydirection and the other two in the opposite direction at one und the sume time.` l

In the Stettin enginchaving one piston' only1 in a cylinder, the steam, during` stroke of the piston, will het against one end of the cylinder and also against the' piston, the said end remaining stationary. Conselghuentely` the piston has to travel tli'e entire length 'of theV cylinder-.during each stroke;- but'with my improvement or invention each piston, during a stroke, travels but about one-'third the length of its cylinder. r In the drawings#- A `-"A denotes the cylinder, and B 'ID the pistons. The two exterior pistons, B D, are connected together by rods a a, `which extend through the middle piston C and smiling-boites ,6 b applied thereto. The rod E of the piston D is tubular, 'and receives in its 'bore the rod F of the'piston C, which slides freely through the said rod E. Connecting-rods G H join -the two pistons `toj u lever, I, fixed on a rocker-shaft, K, provided with en arm or crank, L. A connecting-rod, M, jointed to 'thearm'L and to s crunk, N, serves to transmit motion from the arm L to the crank N, the latter being applied to drivin g-shft, 0. There is or should be a. ily-wheel, l?, on the shaft O, the said shnft bingsuitahly supportedby standards Q Q.4 YThe cross-head 'c of `the piston-rod F slides in guide grooves m'nde in o. carrisge,'R, .ich is ail'xed to the tubular piston-rod E, and slides'betweentwosets of parallell guides S S, arrangedas represented, a. transverse section of `such guides und carriage being shown in Figure 7. Two cylindricnl cases T lfor reception oi' two cylindrical valves U U', placed on the top of the cylinder A, there being por-ts, de, leading from the cylinder into such cases, the sume being .ns represented in iig. 2, Between the valve ceses is a. steam-receiving' chambery-f, und a steam-exhaust chamber, y, they being separated by a. partition, h", (see iig. Passages h t lead from each of suchv chambers into the vulve cases. The valves U U lrevolve freely'within the chambers, dnd each valve is recessed on opposite sides, in manner as shown in figs. 2 sind .4, sndalso in Figure 8, which is u side `view of one of the valves. The shafts of these valves are'connected by two gears it', duly sxed on them where they project beyond the-vulve cases. One o f such-shsft's carries a. bevel-gear, k, `which engages with another such gear, 1,'xed on a. shaft, This latter shaft carries o bevel-gear, n, which worksinto another such gear, Q, xed on the driving-shaft Olv A The steam for operating the engineenters the receiving-chamber f by a' pipe or copduit, P', and is exhausted through n conduit, q, leading out of the exhaust-chamber g. In its' operation on the pistons, the steam will lirst pass through the port d :ind` between thepistons B C, and by its pressure against them' it will 'nieve them in opposite directions. Next, the steam will enter the port e, und will' act against the two pistons ).D, 'und will drive them in opposite directions,'the' exhaust steam between the pistons B C being discharged into the exhaust chamber. The movements of the pistons will produce s continued rotary motion of the shaft O. The crank N is so applied-to n head, r, fixed to the end ofthe shnft O, as to be capable of 'sliding dinmetricnlly scross suchA end. Embrscing the shaft 0,'and fined to stnndard Q, is a cem-plate, S,\ It is formed with n cammed grouve orrecess, t, toreceive s stud, u, extending from'the sliding-crsnk N. The periphery of the .plate S' is parallel to the groove, and s roller or stud, fu', extending from the slide-crank, 'works against the said peri-pher .i ,The cem-plate S is'fsstened to the standsrd Q by screws s s, going through circular slots w w, made in s`snge,`

projecting from vtherplate. This mode of' aiixing the cammed plate to the standard admits of its beingproperly adjusted, as circumstances may require.' :Each of the projecting portions w'wof the cam-plate S is -to cause the piston or pistons,',for a short time, while the crank may be passingeitlier'of the dead-points, 'tobe stationary,

which would not be the ease were the wrist the craukto. turn in a circular orbit.: f -lhe purpose of this'is to' prevent the steam from acting on the pistons a short time, viz, at` the passage of each dead-point, it being caused to ao't on them when the crank may have attained an advantageous position for the connecting-rofl topropelit.

This eects a's'aving of `steam in comparison to what wouldbe required were the wrist of the crank to travel'in a circular orbit.

By the employment of three pistons in ,'ac-ylinder in manner, and witlrvtwo of lthem connected-jas set -forth, I v the pressure of the steam, such as is usually exerted on the head of a cylinder',is employed to e'ect n. move;

meut of one of the pistons when' two of thel'nv are departing fromon'eanother'. Therefore,' with the force'ot' steam acting on. one piston' to propel it, we have the addition of Vthat by which the other piston is propelled in the opposite direction, the two, by their joi-rrt actiou, causing a m'ovementof the rocker-slmft'inlonedirccti'oii.

. The-cylinder, being open at each ond, renders it, easy to gain access to the external pistons for any purpose.

- Iam aware that engines have been made with two, three, or four pistonsin one cylinder, andtherefore I do not claim such. What do claim as my invention in`the above-described engine, is as follows:

,1. I claim the combination. or mechanism whereby the two rods F F o f the engine pistons are enabled to eect rotary motion of the 'crank N or its shaftv 0, as set 'orthfsuchcouibination consisting of the cross-head c, .the slide or carriage R., the connecting-rods G H', the shaft K,ft he lever I,'the varm L, and the connecting-rod M, the whole being arranged and applied.together` substantiallyas specified.

l 2. I also claim the mechanism or combination by whichlthe piston is heldstntionry for a period during the passage by and beyond the dead-point of the crank, such b eing for the purpose hereinbeforedescribed, consisting in the stationary cam-plate S and the 'sliding and studded crank N, constructed, applied togethenand to the standard Q and thc shaft O, substantially in manner and to operate as specified. n

3, And I also claim the combination 'of su'chmechanism, or its equivalent, Vwith one or morebylinclers, their piston or'pistons, and a crank, so connected with the piston or pistons as to be capable ofheingrevolve'd thereby. Y y

" 4. lI also claim the combination or mechanism for supplying steam to'and discharging it-fiom the cylinder I and its three pistons, as specified, the said mechanism consisting of the two rotary valvesU U', their cases T TJ, and inlet and exhaust-chambers fg, and ports, constructed and arranged together and with the pistons and cylinder,'subs tantially in manner and so as to operate as specified.' n

HENRY ).,LOTHROR llvitnesses:

R.. H. EDDY, F. HALE-Jr. 

